package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.ScrollResult;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.FEED_KEY;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@Slf4j
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Autowired
    private IUserService userService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private IFollowService followService;


    /**
     * 根据id查询博客
     *
     * @param id
     * @return
     */
    public Result queryBlogById(Long id) {
        Blog blog = getById(id);
        if (blog == null) {
            return Result.fail("该博客不存在！！！");
        }
        queryBlogUser(blog);
        //查询是否点赞
        isBlogLiked(blog);
        return Result.ok(blog);
    }

    private void isBlogLiked(Blog blog) {
        //获取登录用户
        Long userId = UserHolder.getUser().getId();
        //查询是否点赞
        String key = RedisConstants.BLOG_LIKED_KEY + blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        blog.setIsLike(score != null);
    }

    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        // 查询用户
        records.forEach((blog -> {
            this.queryBlogUser(blog);
            this.isBlogLiked(blog);
        }));
        return Result.ok(records);
    }

    private void queryBlogUser(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }

    @Override
    public Result likeBlog(Long id) {
        //获取登录用户
        Long userId = UserHolder.getUser().getId();
        //查询是否点赞
        String key = RedisConstants.BLOG_LIKED_KEY + id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if ((score == null)) {
            boolean update = update().setSql("liked = liked + 1").eq("id", id).update();
            if (update) {
                stringRedisTemplate.opsForZSet().add(key, userId.toString(), System.currentTimeMillis());
            }
        } else {
            boolean update = update().setSql("liked = liked - 1").eq("id", id).update();
            if (update) {
                stringRedisTemplate.opsForZSet().remove(key, userId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result queryBlogLikes(Long id) {
        String key = RedisConstants.BLOG_LIKED_KEY + id;
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if (top5 == null || top5.isEmpty()) {
            return Result.ok(Collections.emptyList());
        }
        List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        String strJoin = StrUtil.join(",", ids);
       //where id in (5,1) order by filed (id , 5, 1)
        List<UserDTO> userDTOS = userService.query()
                .in("id", ids)
                .last("ORDER BY FIELD (id," + strJoin + ")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(userDTOS);
    }

    @Override
    public Result saveBlog(Blog blog) {
        // 获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        // 保存探店博文
        boolean save = save(blog);
        if (!save){
            return Result.fail("博客保存失败！");
        }
        //查询粉丝
        List<Follow> followList = followService.query().eq("follow_user_id", user.getId()).list();
        for (Follow follow : followList) {
            Long userId = follow.getUserId();
            String key = FEED_KEY+userId;
            stringRedisTemplate.opsForZSet().add(key,blog.getId().toString(),System.currentTimeMillis());

        }
        // 返回id
        return Result.ok(blog.getId());
    }

    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {
        //获取当前用户
        Long userId = UserHolder.getUser().getId();
        String key =FEED_KEY+userId;
        Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet()
                .reverseRangeByScoreWithScores(key, 0, max, offset, 2);
         if (typedTuples==null||typedTuples.isEmpty()){
             return Result.ok(Collections.emptyList());
         }
         List<Long> ids=new ArrayList<>(typedTuples.size());
         long minTime=0;
         int os=1;
        for (ZSetOperations.TypedTuple<String> typedTuple : typedTuples) {
            ids.add(Long.valueOf(typedTuple.getValue()));
            long time = typedTuple.getScore().longValue();
            if (time==minTime){
                os++;
            }else {
                minTime=time;
                os=1;
            }
        }
        String strJoin = StrUtil.join(",", ids);
        //where id in (5,1) order by filed (id , 5, 1)
        List<Blog> blogs = query()
                .in("id", ids)
                .last("ORDER BY FIELD (id," + strJoin + ")").list();
        for (Blog blog : blogs) {
            queryBlogUser(blog);
            isBlogLiked(blog);
        }

        ScrollResult scrollResult=new ScrollResult();
        scrollResult.setList(blogs);
        scrollResult.setMinTime(minTime);
        scrollResult.setOffset(os);
        return Result.ok(scrollResult);
    }
}















